If not, console yourself a higher tier (ebony) and see what changes. Try improving the Dwarven and see if he accepts it.
They generally equip what they perceive to be 'better,' and don't usually take into account enchantments, though they will usually (not always.picky AI) equip upsmithed armor over vanilla of higher tier. Out of curiosity, how early/late in your game did you meet him? Is he in his low level iron or steel armor, or has he already progressed to steel plate? If so, vanilla Dwarven won't do much for him, and you might have better luck with a higher tier armor. Mage? I thought he was a heavy armor, 2H warrior from the Candlehearth Inn in Windhelm.
